Bhagavad Gita · 2.12

न त्वेवाहं जातु नासं न त्वं नेमे जनाधिपाः।न चैव न भविष्यामः सर्वे वयमतः परम्॥

na tv evāhaṁ jātu nāsaṁ na tvaṁ neme janādhipāḥ na chaiva na bhaviṣhyāmaḥ sarve vayam ataḥ param

Never was there a time when I did not exist, nor you, nor all these kings; nor in the future shall any of us cease to be.

— Bhagavad Gita 2.12

Source: Sacred-Texts.com (Sanskrit) + Bhagavad-Gita.io (translations)